README
¶
jsonrepair
A Go library that repairs malformed JSON and JSON-adjacent text into valid JSON
Features
- Missing syntax repair: Adds missing quotes, commas, colons, and closing brackets when the intent is clear.
- Quote normalization: Converts single quotes and smart quotes into valid JSON string quotes.
- Comment removal: Removes JavaScript-style line and block comments.
- Wrapper cleanup: Strips Markdown code fences, JSONP callbacks, MongoDB wrappers, and ellipsis placeholders.
- Literal conversion: Converts Python-style
None,True, andFalseinto JSON literals. - String recovery: Repairs escaped strings, concatenated strings, and common truncated string input.
- NDJSON repair: Converts newline-delimited JSON values into one JSON array.
Installation
go get github.com/kaptinlin/jsonrepair
Requires Go 1.26.4+.
Quick Start
package main
import (
"fmt"
"log"
"github.com/kaptinlin/jsonrepair"
)
func main() {
repaired, err := jsonrepair.Repair("{name: 'John'}")
if err != nil {
log.Fatal(err)
}
fmt.Println(repaired)
}
Output:
{"name": "John"}
API
func Repair(text string) (string, error)
Repair returns the repaired JSON document or a structured *jsonrepair.Error when the input cannot be repaired.
repaired, err := jsonrepair.Repair(input)
if err != nil {
var repairErr *jsonrepair.Error
if errors.As(err, &repairErr) {
fmt.Printf("%s at position %d\n", repairErr.Message, repairErr.Position)
}
}
Sentinel errors support errors.Is:
ErrUnexpectedEndErrObjectKeyExpectedErrColonExpectedErrInvalidCharacterErrUnexpectedCharacterErrInvalidUnicode
Development
task test # Run tests with race detection
task lint # Run golangci-lint and go mod tidy check
task # Run lint and test
Contributing
Contributions are welcome. Open an issue to discuss substantial changes before submitting a pull request.
License
This project is licensed under the MIT License - see the LICENSE file for details.
Acknowledgements
This library is a Go port of Jos de Jong's JavaScript jsonrepair library.
Documentation
¶
Overview ¶
Package jsonrepair repairs malformed JSON strings returned by LLMs, JavaScript snippets, and other JSON-like sources.
Public APIs return errors instead of panicking, and the package does not expose Must* helpers. The only panic-capable paths are package initialization of internal regexp.MustCompile literals, which can fail only if the package source contains an invalid regular expression.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var ( // ErrUnexpectedEnd reports that the input ended before the JSON value was complete. ErrUnexpectedEnd = errors.New("unexpected end of json string") // ErrObjectKeyExpected reports that an object key could not be parsed. ErrObjectKeyExpected = errors.New("object key expected") // ErrColonExpected reports that an object key is not followed by a colon. ErrColonExpected = errors.New("colon expected") // ErrInvalidCharacter reports an invalid character inside a JSON string. ErrInvalidCharacter = errors.New("invalid character") // ErrUnexpectedCharacter reports a character that cannot be repaired in context. ErrUnexpectedCharacter = errors.New("unexpected character") // ErrInvalidUnicode reports an invalid Unicode escape sequence. ErrInvalidUnicode = errors.New("invalid unicode character") )
Functions ¶
func Repair ¶ added in v0.2.8
Repair repairs malformed JSON-like input into valid JSON.
It returns a structured *Error when the input is empty or cannot be repaired.
Example ¶
repaired, err := Repair("{name: 'John'}")
if err != nil {
fmt.Println("Error:", err)
return
}
fmt.Println(repaired)
Output: {"name": "John"}
Example (Error) ¶
_, err := Repair(`{"a":2}foo`)
if repairErr, ok := errors.AsType[*Error](err); ok {
fmt.Println(repairErr.Message)
fmt.Println(repairErr.Position)
fmt.Println(errors.Is(err, ErrUnexpectedCharacter))
}
Output: unexpected character "f" 7 true
Example (Truncated) ¶
repaired, err := Repair(`{"foo":"bar`)
if err != nil {
fmt.Println("Error:", err)
return
}
fmt.Println(repaired)
Output: {"foo":"bar"}
Types ¶
type Error ¶ added in v0.2.3
type Error struct {
// Message describes the repair failure.
Message string
// Position is the rune offset where parsing failed.
Position int
// Err is the underlying sentinel for errors.Is and errors.As.
Err error
}
Error reports a non-repairable parse error and its position.
Source Files
Directories